This invention relates to enzyme technology. In particular, it relates to the enzyme deacetoxycephalosporin C (DAOC) synthase, also known as "expandase", obtained from Streptomyces clavuligerus.
The enzyme expandase mediates ring expansion of penicillin N to DAOC during the biosynthesis of cephalosporin C. DAOC is then converted to deacetylcephalosporin C (DAC) by the enzyme hydroxylase and the latter to cephalosporin C via action of an acetyl transferase.
The bifunctional enzyme, expandase/hydroxylase, obtained from cell-free extracts of Cephalosporium acremonium is described by U.S. Pat. No. 4,753,881. The expandase enzyme obtained from S. clavuligerus provided herein differs from that obtained from C. acremonium in that inter alia it lacks the hydroxylase activity for converting DAOC to DAC.
Because of the importance of the cephalosporin antibiotics in the treatment of infectious disease, the availability of expandase in purified form enables one to study the development of industrial processes for producing these antibiotics. Further, the availability of the enzyme permits one to study the effect of the enzyme on modified substrates which could lead to structurally different antibiotics.